Cyperus involucratus |
Cyperus prolixus |
|
---|---|---|
umbrella flatsedge, umbrella-plant |
mosquito flatsedge |
|
Habit | Herbs, perennial, cespitose, rhizomatous. | Herbs, perennial; rhizomes 3–20 cm × 1–2 cm, indurate. |
Culms | trigonous, 30–150 cm × 1–5(–8) mm. |
stoutly trigonous, thickened, 50–300 cm × 5–30 mm, basally indurate, glabrous. |
Leaves | bladeless. |
V-shaped, with cross ribs, 40–130 cm × 10–15 mm, margins and keel scabrid. |
Inflorescences | heads digitate, 15–30(–36) mm diam.; rays (14–)20–22, (2–)5–12(–20) cm; 2d order rays 0.3–3(–4) cm; 3d order rays sometimes present, 0.3–2.5 cm; bracts (4–)18–22, ± horizontal, flat, 15–27 cm × (1.5–)8–12 mm. |
spikes appressed-ascending, narrowly cylindric, (2–)3–45 mm × (4–)7–10 mm; rays (5–)9–12, 2–22(–30) cm; 2d order rays distinctly flattened, 1–10 cm; 3d order rays flattened, 0.5–3 cm; rachis 2.5–4 cm; bracts (6–)9–10, ascending at 45–75°, V- or inversely W-shaped, (5–)15–90 cm × 0.5–20 mm; rachilla persistent, wings 0.2–0.4 mm wide. |
Spikelets | 8–20, ovoid to linear-lanceoloid, compressed, 5–25 × 1.5–2 mm; floral scales 8–28, laterally whitish or light brown, ± hyaline, medially light brown, laterally ribless, medially 3-ribbed, 2-keeled in proximal 30–60%, deltate-ovate, 1.6–2.4 × (1–)1.2–1.5(–1.7) mm, apex acute. |
(4–)10–35, appressed-ascending, compressed, linear, 7–12(–15) × 0.6–1.2 mm; floral scales deciduous, 6–20, marginally clear, laterally brown, medially green, laterally 2–3-ribbed, medially 1-ribbed, oblong-ovate, (3.2–) 3.8–4.3 × 1.2–1.7 mm, apex spreading, acute to obtuse, mucronulate. |
Flowers | stamens 3; anthers 0.7–1 mm; styles 0.5–1 mm; stigmas 0.6–1 mm. |
anthers 0.7–0.9 mm, connective apex bright red, oblong, to 0.1 mm; styles 0.8–1.3 mm; stigmas 2–3.3 mm. |
Achenes | brown, sessile or stipitate, broadly ellipsoid, 0.6–0.8 × 0.4–0.6 mm, stipe if present to 0.1 mm, apex obtuse, apiculate, surfaces puncticulate. |
brown, sessile, narrowly ellipsoid, 1.8–2.5 × 0.8–1.3 mm, apex ± acute, not apiculate, surfaces puncticulate. |
Cyperus involucratus |
Cyperus prolixus |
|
Phenology | Fruiting early summer–fall. | Fruiting summer. |
Habitat | Damp, disturbed soils, ditches, stream banks | Coastal marshes |
Elevation | 0–100(–800) m (0–300(–2600) ft) | 0–10 m (0–0 ft) |
Distribution |
CA; FL; LA; TX; e Africa [Introduced in North America]
|
LA; Mexico; Central America; South America |
Discussion | Cyperus involucratus has been collected in New York (R. S. Mitchell and G. C. Tucker 1997). Cyperus involucratus is widely cultivated as a water plant in greenhouses and outdoors in warm-temperate or tropical climates. It has long been misidentified in the flora as C. alternifolius Linnaeus, an endemic of Madagascar (G. C. Tucker 1983). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Cyperus prolixus produces large plants, similar in habit to C. giganteus and C. papyrus but easily distinguished by flattened rays. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 150. | FNA vol. 23, p. 167. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycnostachys | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Synonyms | C. amplissimus | |
Name authority | Rottbøll: Descr. Pl. Rar., 22. (1772) | Kunth: in A. von Humboldt et al., Nov. Gen. Sp. 1: 206. (1816) |
Web links |